Keeping Sourdough Culture Alive When You’re Away
The simple solution is to put it in the fridge. A sourdough culture kept in the fridge will stay alive for many weeks and even months. It may not look or smell pretty after a long time in the fridge, but there is probably something still alive in there. It will develop a layer of alcohol on the top (pour this off), and it may smell like acetone and have a darker layer on top, but you can still bring it back to life. If, however, it has developed mould, it is safest to just start a new one. In order to have the most success keeping it alive in the fridge, start with a healthy active culture. Feed the culture, let it ferment for 2-3 hours and then refrigerate.
Another option for long term storage is to dry out a portion of healthy culture on parchment paper (at room temperature or cooler – the heat will kill it). Then place the dried culture in an airtight container in the freezer. To bring it back to life, crush it up and feed it flour and water.